Modeling of Quantum Effects for Ultrathin Oxide MOS Structures with an Effective Potential

Abstract—In this paper, the effectiveness of the effective potential (EP) method for modeling quantum effects in ultra-thin oxide MOS structures is investigated. The inversion-layer charge density and MOS capacitance in one-dimensional MOS structures are simulated with various substrate doping profiles and gate bias voltages. The effective mass is used as an adjusting parameter to compare results of the EP model with that of the Schrödinger–Poisson solution. The variation of this optimum parameter for various doping profiles at different gate voltages is investigated. The overestimated average inverse charge depth by the EP method is quantified and its reason explained. The EP model is a good practical simulation tool for modeling quantum effects but more work needs to be done to improve its accuracy near the interface. Index Terms—Effective potential, modeling and simulation, MOS devices, quantum effect, Schrödinger–Poisson. I